Control means for diesel engines



Pl'n 17 1945, D. F. ALEXANDER l 2,373,735 l CONTROL MEANS FOR DIESEL ENGINES Filed July ISl,` 1940 D/ESEL [N6/NE :ig-,4R r/A/e Mara@ Fun. VAL vf am Heiss-0.9L' ENTOR* s Arf-ry .sw/rr# I BY ATTORNEYS Patented p'r. 17, 1945 UNITED sTArEs PATEN'I" ori-"ion,A

Gemor. MEANS Foa DIESEL ENGINES Donald F. Alexander, Dayton, Ohio, assignor to General'Motors Corporation, corporation of Delaware Dayton, Ohio, a.

Application July 31,1940, serial No. 343,801 s claims. (ci. 12a- 479) This invention relates particularly to automatic V controls for Diesel and other internal combustion engines used to operate refrigeration systems and kindredl apparatus.

Since Diesel engines have no ignition system it is not possible to control them in the manner of ordinary gasoline engines.

It is an objectvof my invention to provide a system forautomatic starting and controlling the operation of Diesel engines.

, It is another object of my invention to provide electrical means for preventing operation of the engin# upon failure of lubrication and yet permit starting. 4 v

It is another object of my invention to provide an electromagnetic control of the governor of a Diesel engine to control the starting andstopping of the engine from a position remote from` 'embodying my invention; and

Fig. 2 is a wiring diagram of the systemshown in Fig. 1.

Referring now to the drawing and more particularly to Fig. l, there is shown a Diesel engine 2l provided with an lelectric starting motor 22 for cranking the engine. This starting motor 22 may be connected to the Diesel engine 2liV by some vsuitable drive such as anEclipse-Bendix or`a Dyer drive. 'I'he engine is provided with a water temperature safety switch 24 for stopping -the engine in case the water temperature should become too high and it is also provided with an oil pressure safety switch 28 for stopping the\ engine if the lubricant pressure is not maintained. A fuel line 28l provided with an electromagnetic fuel valve 30 controls the supply of Diesel fuel 50 oil to the governor 32 which in turn controls the amount of lfuel injected into the cylinders.

A The'governor 32 is provided with a control rod 34 which renders the governor operative. to supply fuel to the engine or inoperative in order to shut off the fuel supply for stopping the enof the control rod 24.

When the engine is to be started it is necessary for the rod 34 .to be moved to the "on position and when the engine is to' be stopped it is necessary to move the rod 34 to the ofi position. The rod 34 is provided with a spring which normally holds it in the o position (not shown). To move the rod 34 to the on position when the engine is started, I provide a solenoid operating means acting upon the rod 34.

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For this purpose the rod 34 is provided with a drum 38 to which is clamped one end of a thin resilient metal strip 38 which is wrapped around the drum and has its free end connected to a spring 40 which in turn connects to the operating plunger 42. This operating plunger 42 gine. A pointer operated-by the rod 34l cooperates with the legends o and on to indi-v cate the inoperative and the operative positions operates within an electromagnet coil 44 which;V

when energized, attracts the operating plunger 42 to pull the spring 40 and the strip 38 to turn the rod 34 to the on position. b

For this initial attraction the electromagnet 4 4 is supplied with current through the conduc tor 48, the spring contact strip 48, the movable contacts I0, the stationary contact 52, the conductor 5 4 and the conductor 58 to the coil 44 Awhich in turn is connected to a conductor 58.

The operating plunger 42 is provided with a Din .l2 extending through a fixed pole piece B0, for

moving the contact strip 4l so that the movable L contact It is moved out of engagement with the contact 52 and into engagement with the contact 44 upon the completion of movement` of the plunger. This causes the electromagnet coil 44 to be supplied with current through the conductor 46, the resistance 8l, the conductor 56 lto the coil 44 which in turn is connected to the conductor 58. The resistance-68 reduces the amount of current flowing through the coil 44 to an amount which is sufllcientl to hold the operating plunger 42 in the operating position without overheating the coil 44. Inasmuch as the operating plunger 42 must be attracted as long as the engine 20 is in operation it is obvious that it is desirable to vkeep the amount of current required as low as possible. I

' Referring now'to Fig. 2, the starting motor 2 is shown connected by the conductors 66 and 68 to .fthe supply conductors 'lll and '|2from some suitable source of electric energy such as a suitably regulated battery'circuit. The starting motor 22 is controlled by a switch 14 which is moved to closed position by an electromagnet 16. An 4 to condensing pressure. The switch 82 may be either manually, automatically or thermostatically controlled. Normally, the switch 82 controls lthe starting and stopping of the system while the switch 80 is used as a safety switch.

Connected to the switch 82 is a conductor 84 which connects to the electromagnetic fuel valve 30 which passes fuel only when energized and-to an indicating 1ight'86 connected in parallel with it to indicate whenever the fuel valveis inthe open position. The fuel valve 30 is connectedby a conductor 88 to the conductor 66 which in turn connects to the normally closed water thermostat switch. and to the oil pressure safety switch 26 connected by the conductor 90 to the suppLv conductor 10.

The switch 82 also controls the electromagnet coil 44 which moves the governor to operative position. The switch contacts S are normally in engagement with the contacts 52 upon the closing of the switch 82, but after the plunger 42 is attracted and moves to its nal position, the switch contact 52 and into engagement with the contact 64, as previously explained in connection with Fig. 1, in order togallow current to iiow through the conductors 96jandf46 as well as through the conductor ||9 to the'electromagnetic coil 16 for closing thestarting motor switch 14. A switch `|2| is also connected in series with the electromagnetic coil 16 and maybe operated by the engine tordeenergize the coil 'I6 when the engine approaches norm'al running speed. This switch |2| maybe a centrifugal or speed responsive switch operated by the speed of the engine or it may be operated by lubricant pressure or some other means which indicates that the engine is in operation. The switch is connected in series withthe switch |2| through the conductor |23 and in turn connects through the conductorl |25 to the supply conductor 10.

The bimetal timer 98, the electromagnet 94 controlled by the bimetal timer 98, the switches magnet 94, together with` the Yconductors |0|,` and and the contact ||3 constitute a timing means which performs the timing func- A switch s2 is connected in shunt with thev contact of the switch 26 to complete the circuit through switch 24 during the starting period, before the lubricating oil pressure can be built up suilicienly to close the contacts 26. This switch 92, like the switches |03 and |09, is operated by an electromagnet coil 94 which is under the control of the switches 80 and 82 and a bimetal timing device 98, connected to the conductor 96. This timing device 98, initially. is connected through a conductor 0| to the switch contacts |03 which in turn connect to a resistance |05 connected by the conductor |01 to the supply conductor 10. When the switch 02 is open, the contacts 92, |03 and are'in the closed position while in the open position are the contacts |09 which control the connection through the conductor ||I with the solenoid coil 94.

Vagravar; f l

IWhen current through the bimetal I l1. 'I'his will render eietive the lubricant pressure switch 26, since at the end of such a period the lubricating pressure should be sufficient to close the -contacts 26 and provide ample lubrication. If theswitch |2| has not been openedby the operation of the engine, the opening of switch I I'| will deenergize the solenoidv 19 .which in turn will allow the opening of the switch 14- to deenergize the starting motor 22v to prevent damage to the starting motor windings and to prevent excessbattery discharge from continued cranking. E.

In this diagram, all the switches are shown in the positions which they assume when the system is deenergized and the engine is idle. To start the system the switch 82 is closed thus energizing the fuel valve 30,l to 'open the supply of fuel to l the Vgovernor 32, and energizing the coil 44, to

make the governor operative to admitY fuel oil into' the engine. As soon as the governor has been moved to operative position, the contact 60 makes engagement with .the contact 64 to energize the solenoid 16 in order to close the starting motor switch 'I4 to cause the starting motor 22- to crank the engine. .The cranking continues normally until the switch |2|opens to stop the cranking after the engine is started. However,l

in case the engine fails to start for any reason whatsoever, the timer 98 will engage contact ||3v tojenergize the coil 94 which opens the switch ||1 to "deenergize the coil 'I6 thereby deenergizing the starting motor 22. In fact, the timer will operate even if the engine starts properly in order to' open the switch 92 to render the oil pressure controlling the starting and operation of a Diesel 92, |I1, |03 and |09 operated by the electro' or-other internal combustion engine. I have also .provided an electrical oil pressure control applicablejto any type of engine.

:- VvWhile the form of embodiment of the invention ,as herein disclosed, constitutes a preferred form, it is to be understood that other forms Tlfnight be adopted. all coming within the scope of which follow.

.--Wht is claimed is as follows: Y

Ysure control for deenergizing said electrically operated means upon failure of oil pressure, and means for preventing the oil vpressure control from cutting off the fuel supplyduring the start-v ing period of the engine.

2. A starting system for an internal combus- I ping the operation of the aavavss' tion engine includingaI governing means provided with a control device having an operative position for controlling the normal operation of the engine and an inoperative position for stopengine, electrically operated means for moving the control device to operative and inoperative, positions, pressure control for moving the control device to inoperative position, and meansfor preventing the oil pressure control from cutting off the fuel supply during the starting period of the engine.

3. A starting system for an internal combustion engine including a fuel controlling device having an operative and an inoperative position, an oil pressure control, means controlled by said oil pressure control for moving said device toy inoperative position upon -failure of oil pressure,

means for cranking the engine, means for preventing the oil pressure control from interfering with starting of the engine, and a timing device for disabling the cranking means.

4. In combinatioma compression ignition enthe normal operation of the engine and an inoperative position for cutting of! the ow of fuel to the engine, electrically operated means connected to.said control device for moving the oontrol device to operative and inoperative positions,

--the normal operation of the engine and an inoperative position for cutting off the iiow of fuel gine and a starting system for theengine including a governing means controlling the fuel supply for regulating the speed ofthe engine, said governing means having a control device provided with an operative position for regulating they normal operation of the engine and an inoperative position forcutting off the now of fuel to the engine, electrically operated means connected to said control device for moving the control e device to operative and .inoperative positions, and

'means rendered effective by the operation of the electrically operated means when energized for reducing the electric current flow through the electrically operated means.

5. In combination,- a compression ignition engine anda starting system for the engine into the engine, electrically operated means connected to said control device for moving the control device to operative and inoperative positions, a starting motor for cranking the engine,

- a second electrically operated means for energizingthe starting motor, means responsive to the operation of the control device to the operative position for energizing said second electrically operated means, and means responsivev to the speed of the engine for deenergizing said second electrically operated means.

8. In combination, a compression ignition engine and a starting system for the engine including a governing means controlling the fuel supply for regulating the speed of the engine, said governing means having a control device provided l with an` operative position for regulating the cludingv a governing means controlling the fuel supply for regulatingv the speed of the engine, said governing means having a control device provided with an operative position for regulating the normal operation of the engine and an inoperative position `for cutting off the flow of fuel to the engine, electrically operated means connected to said control device for moving the control device to operative and inoperative positions, an oil pressure safety switch connected in Aseries circuit relationship with said yelectrically operated means, a shunt for said safety switch, and

a timing device for opening said shunt.

6. In combination, a compression ignition en-v A gine and a starting system for the engine including a governing `xnleans controlling the fuel supply for regulating the speed `of the engine,said governing means having 'a control device provided with an operative position for regulating normal operation of the engine and an inoperative position for cutting loi the fiow of fuel to the engine. electrically operated means connected to said control device for moving the control device to loperative and inoperative positie a starting motor for cranking the engine, a second l,

.electrically operated means for energizing the starting motor, means responsive to the operation of the control device to the operative position for energizing said second electrically operated.

means, means responsive tothe speed of the engine for `deenergizing said second electrically operated means, an oilpressure safety switch for deenergizing said first electrically operated means, a shunt for said safety switch, and a timing device having means for opening said shuntv and for deenergizing said second electrically operated means at the end of a predetermined period of time,

DONALD F. ALEXANDER. 

